Wiring 1982 Heritage Special with m.unit Blue

[SolidSenpai]

Boy howdy, I'm new to the forum and have been doing some work on my XS for the past 6 months or so on and off, it's only now that I have something I'd like some feedback on. I'm doing a sort of tracker build on my bike and will be replacing the majority of the stock electrical components with a motogadget m.unit blue (https://revivalcycles.com/products/motogadget-m-unit-blue), pretty neat piece of tech, although quite pricey. In order to install the m.unit, i'm making a wiring harness from scratch and so I've drawn up a wiring diagram which I'm hoping is all in order, I'd like some feedback on it in case I've missed anything or could improve it. I'm hoping it's straightforward enough without a legend, pardon the quality I used a mouse to draw it.
Also, here's some more info on the m.unit (https://motogadget.com/shop/media/downloads/manual/munit_blue_manual_1.8_en.pdf)

Some other details of my build:
-Kickstart only, removed starter motor/chain and solenoid/relay
-Antigravity 4 cell battery
-Mikesxs regulator/rectifier
-Drag specialties speedometer/tachometer
-LED signals, head/taillight, plate lights etc.
-Lock: I'll be using the bluetooth locking method and a disc lock
-mikesxs pwk carb
-Stock handlebar controls

Cheers, hope this thread can be useful to others wiring an m.unit.

 

[spectra]

I am by no means an electrical person but was able to wire my last project with the older M unit. I used the little M button inside the bars and it made things easy. Only one wire back to the unit to control the lights, blinkers, horn and starter.

 

[Timothy Kelly]

I’ll be keeping an eye on this because I’m using the M-unit Blue as well. I couldn’t figure out how to wire up the Ignition Output, looks like I have it right according to your diagram. My issue is that I’m still using the starter solenoid and don’t know what to do with the red/white wire from it! Got any pics of the bike so far?

 

[Jeff0133]

Feels like R/W should go from finition output to coils then back To tci.

 

[Jeff0133]

..oh and dont forget to ground the tci

 

[Myke Nytemare]

I would be curious as to how this turned out as I bought an M unit almost two years ago and moving twice and family obligations I never got around to finishing my bike. It's sitting in the garage with all of the lights and controls working but I never got the ignition hooked up properly and could definitely use help.

 

[spectra]

I would be curious as to how this turned out as I bought an M unit almost two years ago and moving twice and family obligations I never got around to finishing my bike. It's sitting in the garage with all of the lights and controls working but I never got the ignition hooked up properly and could definitely use help.

What year is your bike? What help are you after?

I wired my 78 with a M unit and wasnt bad at all.

 

[Myke Nytemare]

What year is your bike? What help are you after?

I wired my 78 with a M unit and wasnt bad at all.

It's a 77 400D.I'm all good with the lights and everything that's straightforward...and I even removed the electric start along with the clutch and chain on starter motor to go kickstart only. It's just with the coils (disconnected from the original harness) and the other ignition related wiring (to the engine/plugs) and only the 2 wire in/out "Start" on the M unit I'm kind of unsure how to continue...and wondering if I should buy a Pamco to make life easier. Any help would be great as I have no hope of riding this summer if I can't finish as space/funds/family won't allow me to purchase another bike.

Thanks in advance Spectra,
Mike

 

[spectra]

It's a 77 400D.I'm all good with the lights and everything that's straightforward...and I even removed the electric start along with the clutch and chain on starter motor to go kickstart only. It's just with the coils (disconnected from the original harness) and the other ignition related wiring (to the engine/plugs) and only the 2 wire in/out "Start" on the M unit I'm kind of unsure how to continue...and wondering if I should buy a Pamco to make life easier. Any help would be great as I have no hope of riding this summer if I can't finish as space/funds/family won't allow me to purchase another bike.

Thanks in advance Spectra,
Mike

On mine I had a Pamco and was pretty straight forward.

Yours should be points so what wires are you wondering about ?

 

[Myke Nytemare]

Kind of everything I am finishing up stuff on my car over the next week or two so the bike can have open space in the garage. When I look at SolidSenpai's diagram at the top of this thread, I'm not 100% on where/how the "Stator and R/R" will connect to the main m-unit power wire and how the ignition wire from the m-unit is connected to the "Igniter Unit" and coils on the bike.

Essentially, I have no issues with the lights and m-lock and such, but I am completely blind as to how to wire the ignition so the bike will actually start. I definitely should have done this work when the wiring was fresh in my mind 2 years ago. :-(

 

[BBS360]

You don't have an igniter unit. On your bike you would need a single wire from the Ignition terminal on the munit to your ignition coils. The rest of the ignition coil/points/condenser circuit would remain stock.

What exactly is your issue with the reg/rec stator connection? I'm guessing you do not have a combination reg/rec. Still running stock rectifier and separate regulator?
Either way I'd connect the rectifier ground directly to the m-unit ground and solidly ground that to the frame and motor case.
Also, the 30A fuse should be between the m-unit and the rectifier. Should be no fuse between the rectifier and battery.
Wired as shown in the first post there's a slight possibility that you could fry the m-unit if that fuse ever blew while the bike was in motion.

 

[xschris]

20A fuse on these bikes for main.

 

[Myke Nytemare]

Here is a pic of the wiring in question. Apologies again for being so unknowledgeable on this. It seems if I can figure out how to connect the 4 wires from the coils to the other two "harnesses" in the pic (the two wires coming from the points and the other white molex type connector)... then I would be in a better spot.

 

[Myke Nytemare]

And...just to check, these (or new components in their place) are not needed, right? Seriously I cant remember from 2 years ago everything I did and I also lost the flywheel bolt and have to deal with a dead battery and leaking rear master cylinder.

 

[xschris]

The can is your turn signal flasher relay. You need that.

 

[Myke Nytemare]

The can is your turn signal flasher relay. You need that.

cool...i wont need that either (the m-unit and signals already do work properly), I was more concerned about the other, larger item! Thanks for all of your help and buttoning up the engine/crank with the bolt from you will let me focus on the wiring! Thanks yet again!

 

[xschris]

So the m-unit blinks the turn signals also?

 

[BBS360]

The m-unit has a built-in, load independent, digital flasher.

You probably said somewhere, but are you ditching the electric starter?
The other item pictured is the starter solenoid.
Only required for e-start.

 

[Myke Nytemare]

The m-unit has a built-in, load independent, digital flasher.

You probably said somewhere, but are you ditching the electric starter?
The other item pictured is the starter solenoid.
Only required for e-start.

Yeah the original handlebar button shorted out and I just removed the starter/chain and bought a NOS non electric start handlebar control. Thanks... I really hope I can get get the bike running before the summer! Just need to find time and keep asking questions as everyone has truly been helpful with my wiring ineptitude!